[cmake] Deprecate mysql, odbc, pgsql build options

[hahnjo]

All of them require (optional) dependencies for very little use.

FYI @andresailer

[cern-sft-spi]

Thanks for the heads up.
We still had mysql=ON.

It is enough to turn the options OFF, right?

[hahnjo]

If nobody uses it, yes. The deprecation message will print if the option is set to ON. Eventually you will not want to set the options at all to prepare for removal.

[jblomer]

I'm in favor of deprecating mysql, odbc, pgsql. But not sqlite. It is used, e.g., by cvmfs to use RDataFrame on sqlite data.

[github-actions]

Test Results

    18 files      18 suites   4d 7h 48m 2s ⏱️
 2 694 tests  2 692 ✅ 0 💤 2 ❌
46 762 runs  46 760 ✅ 0 💤 2 ❌

For more details on these failures, see this check.

Results for commit 077b6d1.

♻️ This comment has been updated with latest results.

[hahnjo]

Oh yes, my bad: I didn't realize sqlite was also used in places other than sql. I reverted the change to the sqlite option, we can decide independently if we want to deprecate sql/sqlite and the various TSQL* classes spread between io/sql and net/net. For the moment, I'm focusing on the "easy" deprecations...

[bellenot]

AFAIK, the odbc one is mostly for Windows and comes for free (i.e. It is available when installing Visual Studio). So we could maybe keep it? Or is it too much of a overhead?

[hahnjo]

AFAIK, the odbc one is mostly for Windows and comes for free (i.e. It is available when installing Visual Studio). So we could maybe keep it? Or is it too much of a overhead?

I think the main question for me is whether it is used. Do we know of anybody relying on it? Eventually I'd personally like to see all SQL-related classes deprecated and removed from ROOT because I don't think we should encourage their use.

[bellenot]

AFAIK, the odbc one is mostly for Windows and comes for free (i.e. It is available when installing Visual Studio). So we could maybe keep it? Or is it too much of a overhead?

I think the main question for me is whether it is used. Do we know of anybody relying on it? Eventually I'd personally like to see all SQL-related classes deprecated and removed from ROOT because I don't think we should encourage their use.

OK fair enough, let's deprecate it and we'll see

[guitargeek]

LGTM!